“Behind the White Glasses,” an effusive portrait of the Italian director Lina Wertmüller, the subject of a retrospective at the reopened Quad Cinema, wastes no time turning polemical. “In the whole history of the world, I think there have only been two great women directors, Leni Riefenstahl and Lina Wertmüller,” the critic John Simon says minutes in.

A documentary stuck in a particular moment, perhaps — when Mr. Simon, one of Ms. Wertmüller’s staunchest champions, could proclaim her the most important director since Ingmar Bergman. Whether that sentiment has endured is dubious, and the movie treats Ms. Wertmüller’s poorly received post-1970s career with kid gloves.

The first woman nominated for an Oscar for best director, for “Seven Beauties” (1975), Ms. Wertmüller remains a divisive figure. Her fans saw her as an essential filmmaker of the 1970s. Her detractors pilloried her movies as sexist, politically incoherent and grotesque.

Among her collaborators, Giancarlo Giannini fondly remembers their many films together. Martin Scorsese posits “Swept Away” (1974) as an essential conversation piece in its decade.

At its most enjoyable, Valerio Ruiz’s rambling profile cedes the floor to Ms. Wertmüller, who recalls her creative partnership with her husband, the production designer Enrico Job, and her cultural importance in representing Italy’s south onscreen. Turning 89 this year, she is still a vivacious storyteller whose trademark eyeglasses — she bought 5,000 pairs from the factory, she says — make her pop against even the dullest backgrounds.

Correction:

A film review on April 21 about “Behind the White Glasses,” a documentary portrait of the Italian director Lina Wertmüller, misstated the surname of another director. She is Lois Weber, not Smith.